Attrition mill



ATTRITION MILL Original Filed Aug. 4, 1947 7 Sheets-Sheet l In azen or 0.scar 'wrzlender Feb. 23, 1954 Q C, GRUENDER 2,670,142-

ATTRITION MILL Original Filed Aug.l 4, 1947 7 Sheets-Sheet 2 Fey? Feb. 23, 1954 o. c. GRUENDER ATTRITION MILL 7 Sheets-Sheet 5 Original Filed Aug. 4, 1947 fifth/'Heya Feb. 23, 1954 ATTRITION MILL Original Filed Aug. 4, 1947 '7 Sheets-Sheet 5 y MM o. c. GRUENDER 2,670,142l

Feb. 23, 1954 0, C, GRUENDER 2,670,142

m ATTRITION MILL Original Filed Aug. 4, 194B?` my A y '7 Sheets-Sheet 6 Feb. 23, 1954 o. c. GYRUENDER 2,670,142

ATTRITION MILL Original Filed Aug. 4, 1947 7 Sheets-Sheet 7 Patented Feb. 23, 1954 ATTRITION MILL Oscar C. Gruender, Milwaukee, Wis., assignor to Nordberg Manufacturing Company, Milwaukee, Wis., a corporation f Wisconsin Original application August 4, 1947, Serial No. 766,044. Divided and this application May 13, 1950, Serial No. 161,769

claims.

My invention relates to an improvement in ne reduction or attrition mills.

One purpose is to provide an improved mill in which materials may be reduced to substantial ineness.

Another purpose is to provide an improved mill in which hard materials, such as ores, can be reduced to extremely fine sizes.

. Another purpose is to provide an improved liquid seal for such mills.

Another purpose is to provide an improved main frame for such crushers and mills.

Another purpose is to provide an improved attrition liner.

Another purpose is to provide improved locking means for the attrition liner.

Another purpose is to provide improved centering and bearing means for the actuating eccentric of such mill or crusher.

Another purpose is to provide improved means for preventing rotation of the bowl of such a mill or crusher in relation to the main frame.

Another purpose is to provide improved lubricating means for such mill or crusher.

Another purpose is to provide improved sealing means for the top of the head and eccentric of such mill or crusher.

Another purpose is to provide a pneumatic release for such mill or crusher.

Other purposes will appear from time to time in the course of the specification and claims.

The present application is a division of my co-pending application Serial Number 766,044, now Patent #2,509,920 for Attrition Mill, iiled in the United States Patent Oirice August 4, 1947, Another copending application, Serial No. 317,193, constitutes a, continuation-in-part of the presentapplication.

I illustrate the invention more or less diagrammatically in the accompanying drawings, where- 111:

Figure l is a vertical axial section;

Figure 2 is a similar partial section on an enlarged scale;

Figure 3 is a section on the line 3--3 of Figure 1;

Figure 4 is a section on the line 4-4 of Figure 2;

Figure 5 is a section, on an enlarged scale, on the line 5--5 of Figure 4;

Figure 6 is a section on the line 6--6 of Figure 2;

Figure 'I is an enlarged detail of the structure shown in Figure 6;

Figure 8 is a section on the line 8--8 ci Figure 7; l

Figure 9 is a section, on an enlarged scale,.on the line 9-9 of Figure 7;

Figure 10 is an enlarged detail, in vertical radial section, of the liquid sealing portion of the device;

Figure 11 is an end elevation taken along --the line II-II of Figure 3;

Figure 12 is a partial vertical axial section through an upper portion of the feed plate structure;

Figure 13 is a detail of a sealing ring shown in Figure 12; and

Figure 14. is a section, on an enlarged scale, on the line I4I4 of Figure 13. y

Like parts are indicated byV like symbols throughout the specication and drawings,

Referring to the drawings, I generally indicates any suitable base upon which the crusher or attrition mill is mounted. 2 generally indicates a circumferentially extending main frame member having a top, outwardly extending, generally horizontal flange 3, and 4 is a bottom flange, the two flanges connected and strengthened by the vver-- tical ribs or webs 5. B is any suitable grouting on base I and upon which the main frame is positioned.

Mounted on, and removably secured to lthe upper edge of the main frame, and overlying the ange 3, is a normally fixed -abutment member or bowl supporting or receiving abutment ring '1 having a downwardly extending, circumferential outside flange 8 which surrounds and conforms to the edge of the flange 3. The ring has an inner, upwardly extending bowl abutment portion or bowl receiving ilange 9, having a generally conic, outwardly tapered inner face I0, a flat'top face I I, and a generally cylindrical'outer face I2'. I3 indicates three suitable U-shaped arm elements or inwardly extending'radial ribs connecting and supporting the central hub I4.

Mounted within the hub I 4 is the preferably somewhat conic central post I5 which conforms to a similarly formed inner face I6 of a generally central aperture of the hub I4. The post I5 has a downwardly reduced lower end portion I1, shown as screw-threaded as at I8,- The post l5 has an upper and generally cylindrical portion I9, shown as provided with an exterior, circumferential oiling slot 20, and a horizontal oil passage 20a, which may suitably communicate with an axial oil passage 2| connected to any suitable oil delivery duct 22 from a suitable source oIoil or lubricant. Y

23 is a nut, inwardly screw-threaded to receive the exterior threads I8 of the lower end of the shaft I5. It has vertical slots at the lower portion, as indicated at 24, and an upper, out',

wardly extending flange 25 in a supporting ring or securing member 26, removably secured to the lower end of the hub I4, as by any suitable securing bolts 21. Dust entrance is prevented by any suitable packing 28. It will be understood that when it is desired to remove the post I5, nut 23 is rotated in the opposite direction, causing the underside of the ange 25 to bear against the supporting ring 26. This results in an upward thrust on the threads of the post I5, freeing it from contact with the surface I6 of the hub i4. By continuous rotation of the nut, the post I is raised until the threads are no longer in engagement, permitting upward removal of the post. It will be understood that when the post is in position, it is fixed, and that the outer and generally spherical surface of its upper portion I9 constitutes a central support for the later described crushing head and its actuating means.

Surrounding the post portion I9 is an eccentrically apertured sleeve 30, which constitutes a unitary actuating member for gyrating the below-described crusher head and for rotating the belowdescribed feed plate 54. It may be supported at its lower end as by a bearing ring 3I held against rotation in relation to the sleeve 30, as by pins 32. It rests upon the normally fixed bearing ring 33, suitably held against rotation in relation to the upper end of the sleeve I 4. 34 is a bevel gear which may be keyed to the eccentric sleeve 30, which meshes with a pinion 35 on the drive shaft 36 rotated by a suitable exterior pulley 31, shown as channeled as at 38 to receive V-belts or other suitable driving means. The gear has a circumferential vertical iiange 34a located within the circumferential ring 34h, integral with the arms I3. In the event of shaft failure, the gear and eccentric will move only slightly laterally, because the flange 34a will prevent such lateral displacement. Any suitable bearing assembly may be employed for the shaft 36. I illustrate a surrounding sleeve 39 carrying suitable bearing units 40 and 4I at its opposite ends. 42 generally indicates any suitable sealing structure. The sleeve 39 is shown as having an exterior closure flange 43, with which it is integral, which fits in and closes an aperture surrounded by any suitable sleeve 44, forming part of the main frame circumferential wall 2. 45 is an oil supply passage, and 46 a suitable oil removal passage.

It will thus be clear that, in response to belts engaging the drive pulley 31, the eccentric sleeve 30 will be rotated about the upper central post portion I9. The eccentric sleeve 30 is shown as having an upwardly extending portion 56, the upper end of which is shown in greater detail in Figure l2. Secured to it, as by screws 5I is a feed plate 52 having a circumferentially extending, downwardly faced slot 53. As will be clear from Figure l2, this slot is described about a center, indicated at X, which is eccentric to the center Y, about which the eccentric sleeve 30 rotates. The result of the rotation of the eccentric sleeve 30 is a rotation of the plate 52.

Any suitable top wear plate 54 may be secured to the plate 52, as shown in Figure i, as by suitable screws 55. Thus material dropped upon the top of the feed plate 54 will be laterally, centrifugally thrown, as will later appear.

56 is any suitable bearing sleeve between the outer surface of the post I9 and the inner surface of the eccentric sleeve 30. It may-be apertured as at 51 for the admission of oil, such aperture being aligned .with the .cil aperture 53 ex- 4 tending generally radially through the eccentric sleeve 30.

60 generally indicates a gyrated crushing head which is gyrated about the center, in Figures 1 and 2, at A. It includes an upwardly extending hollow stem portion 6 I, externally screw-threaded as at 62. B3 is a sealing ring bearing against the inner surface of the hollow stem 6 l but seated in a circumferential, outwardly opening slot 64 in the upper end portion 50 of the eccentric sleeve 3B. It will be noted that the slot 64 is normal with the inclined axis X, and lies in a plane slightly inclined from the normal in relation to the center Y.

The head 60 is provided with a downwardly eX- tending sleeve portion or bearing sleeve 65 which surrounds the eccentric sleeve 30 and is separated from it by any suitable wear-taking sleeve or liner 61 with its oil-passing aperture 68 aligned with an oil passage 69 in the lower portion of the head 65. The head also includes any suitable connecting webs 10 and a spherical bearing portion 1 I, the exterior and generally spherical bearing surface of which rest upon any suitable upwardly concave bearing or spherically surfaced supporting ring 12 mounted on an intermediate portion or extension of the main frame 2, as shown in Figure 1, which surrounds, but is outwardly spaced from, the post portion I9. 13 is an annular oiling passage in the ring 12. Oil holes connect this passage with the annular oiling passage 13a, and oil holes 14 conduct the oil to the interior of the machine. It will be noted that the inner surface of the sleeve 65 is inclined in relation to the center Y, but is concentric with the center X. It will be understood that as the eccentric sleeve rotates, it imparts to the head 60 a gyratory movement about the center A.

15 indicates a crushing or attrition member or somewhat conic die or mantle resting upon an appropriately formed upper supporting surface 15 of the head Gil. The die 15 is held in position by a generally conic positioning thrust member or sleeve 11 which is formed at its upper edge, as at 18, to receive a locking member or thrust ring or securing nut 19. The thrust ring or nut 'I9 is inwardly threaded, as at 8D, to conform to the exterior threads 62 of the upper hollow stem portion 6I of the head 6D. The ring or securing nut 19 is also provided with an upwardly extending sealing ring portion 8i which extends into the circumferential, downwardly opening annular channel or groove 53 in the lower surface of the plate 52. Suitable sealing rings or packings are provided, as at 83, 34 and 85, received in appropriate annular recesses, whereby the ring BI is sealed at both sides. An upper sealing member or ring is positioned in the slot 53 and is held against rotary movement, as by suitable positioning pins 81 extending into apertures 88 in the upper part of the plate 52. The ring 86 is provided with an exterior sealing member 89, which may be of rubber.

It will thus be understood that whereas the head 60 may gyrate about the center A, in response to rotation of the eccentric sleeve 30, leakage of oil from the inside to the outside is prevented, and also the inward penetration of dust particles from without. Nevertheless, the plate 52 and its outer wear-taking feed plate 54 may rotate in unison with rotation of the eccentric sleeve 30, whereas the head BIJ and its weartaking die 15, rotate only slightly, as they gyrate.

The head 66 is provided with an outwardly ex- Y.: tending portion 9B uponwhich the exterior apron 5I may be e0u`red. 92 indicates the downwardly and inwardly extending guard secured to the outer edge of the portion 90 of the head. Its lower edge 93 extends into a gutter 94 formed in the circumferentially extending annular portion 95 of the main frame. A suitable liquid, such as water, is delivered to the gutter 94, for example, along any suitable duct 96, a constant circulation of water being maintained. The water tends to ll the gutter 94 and to ow thereabout, overflowing inwardly over the edge of the inner dam 91. This darn may be in the form of a circumferentially extending ring defining the space 98 from which one or more outlet passages 39 may extend. Such passages are shown in Figures 1, 2 and 10, and are directly above the U-shaped arms I3.

'In Figure 1 is indicated a closure plate |00 through which water may flow along any suitable discharge pipe |I. As will be clear from Figure 10, I may provide any suitable splashpreventing elements. I illustrate, for example, a horizontal ring |02 extending outwardly intermediate the upper and lower edges of the dam 91. I illustrate, also, inwardly extending rings |03 and |04 inwardly extending from the outer inclined wall |05 of the gutter 94. I illustrate a vertical ring |00, shown as generally cylindrical and as downwardly depending from a lower portion of the head extension 90. In addition, I illustrate the surrounding and preferably flexible packing ring |01, upwardly extending from the upper outer edge of the gutter 94 and held and protected by a circumferentially extending metal ring ||0.

In order to cause a positive movement of the water along the bottom of the gutter 94 I provide the following structure. The water inlet passage 96 delivers water through a duct ||5 to an annular passage H5 located -beneath the bottom of the gutter 94 and closed by a plate or plates ||1 secured in position, for example, by suitable screws |8. It will be noted that the screws enter the upper surface of a ledge H9, located at one side of the passage IIB, as shown in Figure 10. The water which is delivered to the passage ||6 along the duct ||5 may escape through the plate or plates |1 through one or more upwardly extending discharge passages |20. These passages are partly closed by delector plates |2| spaced upwardly from the uper surface of the member ||1, as by spacers |22, which leave a free space |23, as shown in Figure 8. With water being delivered under pressure to the passage ||6, and escaping through the outlets |20, the escape passage |23 delivers water along the bottom of the gutter 94; that is to say, along the upper surface of the plate or plates |1, in the direction of the arrows of Figure 8, The result is a positive circulation of water along the bottom 'of the gutter 94, the water so circulating tending to swirl and scour, and remove foreign particles. These particles, so far as they penetrate over the upper edge of the member |01, and into the interior of the gutter 94, are therefore carried over the upper edge of the dam 91 and are removed along the passages 99 and the discharge ducts |0I. Note, as in Figure '7, that the outlet |23 may be somewhat outwardly flared, as at |23a.

As many of the discharge passages may be employed as is convenient or necessary, twelve being shown in Figure 6. Whereas the number may be varied to suit the needs of a particular situation, Il'nd that a structure with twelve ofthe delivery 'passages |23 and three of the `outlet passages 99 works.eiicientl-y.vv Thus, when the eccentric 6 sleeve 30 is rotated, and the feedplate 54 is rotated, and the die 15 is gyrated, there is no perceptible entry of dust into the necessary series of bearings. And oil may be delivered from any suitable source, along the oil inlet duct 22, and may ilow through the above-described oil ducts and such additional ducts as are shown at |25, etc., back to the oil return pipe |20. f

Opposed to the attrition die 15 is the upper attrition liner or ring |30. It will be noted that the opposed surfaces of the members 15 and |30 are generally conic, but converge somewhat to-- ward the outlet or lower and outer end of the attrition zone defined between the two members. The bowl liner |30 is mounted on a tiltable or releasable bowl and support, which will now 'be described. The bowl structure proper, indicated at |3|, has a bottom web or portion |32 Vand a preferably integral outer cylindrical portion |33, exteriorly screw-threaded, as at |34, and having an upper annular portion |35 with a more or less conic inner surface |30 and an outwardly extending top flange |31. It is provided, also with generally radial ribs |38 having upper edges which downwardly and inwardly prolong the con-ic surface |36, and which receive a conic feed hopper or feed directing ring |39, removably secured, as by members |40, to the surface |36, and overlying the upper inner edge of the bowl liner |30. It will be noted that the liner |30 has an upwardly extending annular portion |4| with an outwardly extending top ange |42 which may be apertured or provided with exteriorly open notches 42a. Keys |43a are secured to a split or segmental threaded locking ring |43, the keys entering the exterior notches |42a, preventing rotation of the locking ring in relation to the member |30.

The ring |43, in turn, is externally screwthreaded, as at |44, to conform to interior threads |45 on the annular locking member |46 which seats in a recess or on a shelf |41 on an upwardly and inwardly extending bowl bottom portion |32a. The ring |46 has upwardly ex-4 tending lugs |48 adapted to be received in notches |50 in segmental locking plates |49. The plates |49 have external notches |5| adapted to engage forward edges of the bowl. Thus, since the ribs |38 are fixed, the locking plates 49,. when in the position in which they are shown in Figures 2 and 4, prevent any rotation of the' ring |46. This, in turn, holds the bowl liner |30 upwardly drawn against the -conic surface of the bowl portion |320.. However, when removal of the liner |30 is desired, it is a simple matter to lift the locking plate |49 upwardly out of locking position, and to knock the ring |40 to the re' leased position, by operating a tool or hammer against the upwardly extending lugs |48. The delector gutter |39, meanwhile, both protects the above described structure and directs the feed downwardly and inwardly toward the attrition zone between the members 15 and |30. i

Any suitable feed-directing or limiting means may be employed, as shown in Figure 1. It may include, for example, an outer circumfe'- ential ring |6| an inner and feed aperture defining ring |62, and suitable reinforcing or connecting members |63. The structure, as a whole, may rest upon the portion |35 of the bowl strucA` ture, being centered in any suitable shelfoi'` circumferential ledge |64. A The bowl structure proper is adj ustably mount-1 ed in a bowl support, generally indicated as |10." It includes a generally cylindrical inner portion .|1|, inwardly screw-threaded, as at |12, to conform to the exterior threads |34 of the bowl wall |33. The bowl may be raised or lowered by a relative rotation of the portions |33 and |1|. When the adjustment has been made, the parts may be locked against relative rotation bythe locking or thrust screws |13 which pass through the flange |31, and may be locked in position as by lock nuts |14. Any suitable packing or dust guard means may be employed, as at |16 and |11. The outer dust guard |11 bears against the inner surface of the cylindrical ring |18 which may be welded or otherwise secured to the exterior of the bowl portion |31.

It will be understood that any suitable means may be employed for imparting relative rotation, for adjustment purposes, to the members |1| and |33. I illustrata, for example, the windlass |80 with its actuating handle |8| and its flexible element |82. The details of this structure do not, of themselves, form part of the present invention, and will not be further described, it being understood that any suitable means may be employed for imparting an adjusting rotation to the member |33 in relation to the member |1|. It will be understood that the exterior of the member 11| is provided with a plurality of vertical recesses |1|a. I may loci: the parts against relative rotation by a suitable removable locking block |83, shown in Figure 1 as removably secured to a lower portion of the ring |18, as by any suitable locking screw I. The member |83 has an inwardly extending lug |85 adapted to enter one of the slots or channels |1|a.

The portion |11 has an outwardly extending bottom flange |90 with a plurality of lateral arcuate edged bosses or enlargements |9| apertured, as at |92, to receive tension rods, which will later be described, but which permit the ring support structure to tilt upwardly away from the flange 9, against which it normally seats, when tramp iron or uncrushable material is present in the crushing or attrition zone. In order to prevent rotation of the bowl support and to insure that the parts seat or are centered properly when the bowl support drops back into the normal position -in which it is shown in Figure 1, I provide a plurality of lugs |93, outwardly extending from some of the bosses |9| and carrying an arcuate surfaced abutment |94 which may be the head of a removable screw or bolt |95, held in position, for example, by a nut |96, as shown in Figure 11. The arcuate or domed surface of the member |94 abuts against a positioning pin |91, suitably hardened, which is removably positioned on the flange 1. It may, for example, pass through a boss 1a, and have a reduced shank |98, the lower end of which is screw-threaded, as at |99, to receive any suitable securing nut 200.

The bowl support |1| may normally 'be held in the position in which it is shown in Figure 1, by any suitable releasable means. I illustrate, for example, the through the apertures |92 and have enlarged upper holding heads 206, downwardly domed as at 201, to engage seating pockets 208 which surround the upper ends of the apertures |92 through the bosses |9|. These pockets perform a centering function, as is shown in Figure 1, whereby the member 205 is kept out of contact with the walls of the apertures |92, with a consequent prevention of wear.

The anges 3 and 1 are apertured, as shown tension rods 205 which pass E at 209 and 2|0, to clear the member or rod 205. The rods extend downwardly through suitable apertures 2|| in any suitable yoke or yokes 2 I2, normally held in downward position by thrust pistons 2|3 in suitable cylinders 2|4 secured to the lower surface of the main frame flange 3. It will be understood that a suitable liquid or fluid, under proper pressure, is delivered to the interior of the piston structure so formed, in such fashion that the downward thrust against the member or members 2|2 normally exceeds the crushing or attrition stress. But when a predetermined crushing or attrition stress is exceeded, or when uncrushable material passes through the crushing zone dei-ined between the members 15 and |30, then the bowl structure can tilt upwardly without breakage. It will be understood that when the pressure within the cylinder structure is released, the entire bowl structure may readily be upwardly removed, either for repair or replacement, or to clear the uncrushable material from the crushing cavity. The details of the pressure maintaining means are not herein shown, since they do not, of themselves, form part of the present invention, and are shown and described in my earlier filed, copending application Serial No. 697,227 now abandoned, Pneumatic Release for Cone Crushers, nled in the United States Patent Oice on September 16, 1946.

It will be realized that, whereas, I have described and illustrated a practical and operative device, nevertheless many changes may be made in the size, shape, number and disposition of parts without departing from the spirit of my invention. I therefore wish my description and drawings to be taken as in a broad sense illustrative or diagrammatic, ratherl than as limiting me to my precise showing.

'I'he use and operation of the invention are as follows:

I illustrate an attrition or reduction mill in which a gyrated head gyrates about a predetermined center A within a normally fixed bowl. The method carried out in my mill is described and claimed in my copending application Serial No. 766,043, now Patent No. 2,509,919 Method of Reduction by Attrition, filed in the United States Patent Office on August 4, 1947.

It will be understood that whereas I have illustrated a grinder or fine reduction mill, nevertheless many of the features, herein shown may be employed in connection with gyratory Crushers in which a head is gyrated within a bowl. Thus the means for gyrating the head is equally applicable to coarse and fine reduction gyratory Crushers, and the feature of a rotated feed plate, in connection with a gyrated head, properly lends itself to use with fine, intermediate, and coarse gyratory Crushers. The same is true of the water-seal above described.

In considering the general application or operation of the various features above described, I employ a normaly xed central post I9 about which the eccentric sleeve 30 rotates. The eccentric sleeve performs the double function of gyrating the head and of rotating the feed plate 50. The material passing through the attrition or crushing zone is reduced by the gyratory movement of the head 60, the material being actually engaged by the die 15 and the liner 30. The water seal is advantgaeous in that water is caused to rotate in the trough or gutter 94. The various outwardly extending anges or rings, as shown in Figures 2 and 10, prevent mamma splashing of the water and :escape of thexwater ynutwardly rover .the .edge of `:the trough :or gutter &4. The rotationof .the Jvvaterin the .gutter :or Atrough causes .it to .adhere f to :the .walls, and vthis zsurface tension lessens vthe :tendency of the :water Sto :partake of .the ,gyratory .movement of ithe member 19:2 tor .of .any quart fassociated .with ithe iheaditself.

'lhe sealing -ring 8.6, shownias expansible :1in `Figures 13 and `14, -located :in 'the top plate 52,;is @preferably fformed in halves, and rotates `,with rtheifeedplate support 52throughfthe mediumzof ithejpinsl. A rubberring-orwasher 89iisitted into an exterior recess in lthe :ring halves ,8.6. iWhen :the .ring halves 86 zlrotate, with the ifeed plate support 52, centrifugal forcerurgeseachhalf ioutwardly, 'causing it toaurge ,the rubber :ring :onwasherS against the outer-wall of thesl'otiSS of the feed plate support-5.2. .Thus the ring does not bear heavily "against'the 'contacting face of the fhead nut or its upward1extension 8l. The frubber ring 89 rfur-ther effects -a perfect 'seal fagainst .the entrance Aof dust at ithe outer 'diameter of the ring. And since the ring 86 bears against the top of the head nut, no dust can enter underneath the ring. The ring halves 86 may be made of a lead-base bronze, and no lubrication is required. No matter what wear takes place to change the vertical position of the ring 86 in respect to the contacting parts, it will automatically nd its new position, and function effectively to seal the top of the machine against the entrance of dust.

The above-described means for holding the die in place are of the self-tightening type. The nut 19 is threaded to engage the exterior threads 62 on the head, and bears against the intermediate members 11, which contact the thrust downwardly and outwardly against the die 15, holding it constantly rmly in position. The upper attrition member or liner I 30 is also of the selftightening type, because the threaded locking ring |43 is forced to rotate with it.

It will be understood that my improved main frame and my improved main shaft or central post structure while useful in connection with the attrition mill described and claimed in my copending application Serial No. 766,043, Method of Reduction by Attrition, led in the United States Patent Oice on August 4, 1947, and in my copending application Serial No. 766,044, Attrition Mill, led in the United States Patent Office on August 4, 1947, may advantageously be used in connection with gyratory crushers in general.

I claim:

1. In crusher or attrition mill, a circumferential outer frame member, a hub therewithin, unitary generally radial structural elements connecting the hub and the circumferential outer frame member, said hub having a generally conic upwardly enlarging bore extending therethrough and open at top and bottom, the wall of said bore being unitary with the hub and being circumferentially unbroken, a, normally xed crusher shaft having an unsupported upper end and a lower portion tapered to conform to the internal tapered conic surface of the hub and having an upwardly extending generally cylindrical portion free at its upper end, the two portions of the shaft being generally of equal length, means for urging the shaft downwardly against and within the solid tapered conic surface of the hub in rm locking relationship, including a nut abutting the bottom Y 0! the hub and having a screw threaded aperture.

the shaft 'having -a downwardly extended screw threaded'endfportionradaptedorrscrewxthseaded engagement :with thelnut, and means for securing the nut to the hub including a circumferential zmember secured to the hub, the'nutihatng an upper, `.circumferential .portionlextending outwardlyinto a space'be'tween the 'hub and such holding member, the nut ihaving an `expused downwardly 'extending v'portion sbelow said ilhuld- *injg member adapted -to `receive 'actuating fmeans.

A"2. In a 'replaceable abutment for crusher or 'attrition mills 'having -a circumferential *main frame memberwitha 'top flangeand atbowl-supporting Atilting vring positioned `above the main vframe member, i a Vone-piece abutment 'ring ihaving a generally Ahorizontally extending ibedyfpor- Ltion t-witha downwardly extending circumferential centering flange aboutf'theouter edgem'fsaid ibody por-tion, -said -iian-ge 1'being positioned fand rla'daptedto engage thecuteredgeo'f theitoplflange 0'1" such main frame -member hin ascenteringirelaftionship, -said A'ring -body portionhaving -`adjacent its 'inner edge an -upwardly -fex'tending centering flange for the bowl supporting tilting ring, said fiange having a generally cylindrical outer surface and an upwardly expanding, tapered inner surface, said abutment ring being apertured to permit the passage of securing elements downwardly therethrough.

3. In a sealing assembly for a crusher or attrition mill having a circumferential outer frame member and a gyratory head therewithin and means for gyrating it about a predetermined center, a circumferential open-topped liquid receiving trough positioned within said main frame at a level substantially below the center about which the head is gyrated, said trough having circumferential outer and inner walls, duct means for delivering a sealing liquid to the trough, a skirt movable with the head and having its lower edge portion extending downwardly into said trough, at all positions of the head, to a level below the upper surface' of the liquid in the trough, the outer wall having an upper edge located at a level above the level of liquid in the trough, the movable skirt being at all positions of the head closely adjacent and in part above the upper edge of the outer wall, whereby entry of dust is substantially prevented, the inner wall having a circumferential spillway edge lower than the outer wall, the line of entry of the skirt into the liquid being substantially nearer the outer wall than the inner wall, and a discharge outlet located inwardly of the inner wall, positioned and adapted to receive the liquid which overflows the inner wall, whereby the outlet is at all times shielded by the penetration of the skirt into the liquid, the circumferential spillway of the inner wall being effective to maintain a predetermined level of liquid in the trough.

4. The structure of claim 3 characterized by and including at least one generally horizontal xed circumferential battle ring extending from an internal surface of one of the trough walls at a level below the upper surface of the liquid in the trough, and substantially above the bottom of the trough.

5. The structure of claim 3 characterized by and including a plurality of xed generally horizontal circumferential baille rings projecting inwardly from the opposite side surfaces of the trough walls at levels below the upper surface of the liquid in the trough, said bailles being ar- 11 ranged in staggered relationship, and being substantially above the bottom of the trough.

OSCAR C. GRUENDER.

References Cited in the file of this patent 5 UNITED STATES PATENTS Number Name Date 243,545 Gates June 28, 1881 271,138 Sharpneck Jan. 23, 1883 lo 652,208 Hadeld June 19, 1900 768,955 Russell Aug. 30, 1904 1,029,742 Capen June 18, 1912 1,145,629 Symons July 6, 1915 1,226,275 Symons May 15, 1917 15 1,309,104 Sanborn July 8, 1919 1,402,255 Sanborn Jan. 3, 1922 1,537,564 Symons May 12, 1925 1,553,202 Symons Sept. 8, 1925 1,791,584 Symons Feb. 10, 1931 20 1,817,044 Symons Aug. 4, 1931 1,863,529 Symons June 14, 1932 1,868,338 Symons July 19, 1932 Number Number 12 Name Date Symons Oct. 15, 1935 Jacobson Sept. 15, 1936 Gruender Aug. 31, 1937 Campbell Oct. 11, 1938 Brown Nov. 1, 1938 Fahrenwald Feb. 21, 1939 Rumpel May 16, 1939 Gruender Dec. 3, 1940 Fahrenwald Sept. 2, 1941 Browning June 30, 1942 Gruender Dec. 22, 1942 Gruender Dec. 29, 1942 Gruender Feb. 9, 1943 Gruender Feb. 15, 1944 Eben June 6, 1944 Gruender Oct. 10, 1944 Rumpel Oct. 15, 1946 FOREIGN PATENTS Country Date France Sept. 18, 1939 Germany Feb. 17, 1933 

